Pittsburg is an industrial city in eastern Contra Costa County, California in the East Bay region of the San Francisco Bay Area. The population was 63,264 at the 2010 census. In 1849, Colonel Jonathan D. Stevenson (from New York) bought the Rancho Los Medanos land grant, and laid out a town he called New York of the Pacific. By 1850, this venture failed. With the discovery of coal in the nearby town of Nortonville, California, the place became a port for coaling, and adopted the name Black Diamond, after the mining firm that built the Black Diamond Coal Mining Railroad from there to Nortonville. Because of the industrial potential of the site, a name change to Pittsburg was proposed in 1909.